Alloy metal



Patented Aug. 24, 1937 I UNITED STATES ALLOY METAL Jacob Karts, Teaneck,and Clemens A. Laise,

Tenafly, N. 1., assignors to Eisler Electric Corporation, Union City,J., a corporation of Delaware No Drawing. Applicationvoctober 16, 19:6,Serial No. 1o5,asc

2 Claims.

This invention relates to a new alloy composition in the form of rod,sheet and wire, or any other convenient shape or casting, said wirebeing especially useful in the incandescent lamp,

radio and television industry, as well as for electrical contactpurposes.

The invention provides a substantially non-- Essentially our improvedalloy metal comprises Monel metal to which we add refractory metals suchas tungsten and molybdenum and a small proportion of manganese. Theseadditions of refractory metals in no way impair the non-corrosiveproperty of the Monel metal and .at the same time impart to the metal acertain amount of hardness and a considerable amount of tensilestrength, so that the resultant alloy may be drawn down to much finersizes of wire and so that said wires can be used in operations where thewire is subjected to considerable stretch.

" As above mentioned, our improved alloy metal may also be used forcontact points and other electrical purposes because of itsnon-corrosive characteristics and because of the increased hardness thathas been imparted to the Monel metal through the addition of therefractory metals molybdenum and tungsten. The addition of theserefractory metals, furthermore, \increases the resistance of thecomposition, the tensile strength of the wire and the elastic limit ofthe same.

The added manganese is so adjusted or controlled that at no time will itexceed 5%, and preferably ranges from to 2%. The presence of themanganese improves the mechanical working of the metal and imparts ahigh electronic work function which is of'particular advantage when thewire is used as grid wire for radio tubes.

The refractory metals added to the Monel metal consist essentially ofmetals of the sixth group of the periodic system, especially suchrefractory metals as are non-corrosive at room temperature. In itspreferred form our im- 7 proved alloy comprises Monel metal and addedmolybdenum and a small percent of tungsten.

The addition of these refractory metals usually ranges from 5% to 20%. g

The Monel metal consists essentially of 28% copper and 72% nickel. Ourimproved alloy, therefore, consists substantially of about 62% 5 nickel,25% copper, 10% molybdenum, 1% tungsten and 2% manganese. The alloy may,however,'also be adjusted so the molybdenum and tungsten content mayeven be raised to as high as 20%.

The alloy may be produced according to methods well known in the art,our preferred method, however, being to take-a bar of Monel metal eitherin. cast form or in rod form, boring said bar but and introducing intothe center of the bar the ingredients to be added, namely, molybdenum,tungsten and manganese, preferably in the form of small pieces. It ispreferable to close the casting or cavity so that air does not have freeaccess to the tungsten and molybdenum before the-Monel metal is broughtup to a fusion point. The Monel bar or rod, together with the additionalingredients, are placed into a suitable crucible, preferably of lime,which in turn is heated up either in a gas, oil or electric furnace, thelatter preferably of the induction type, to a temperature high enough tomelt the Monel metal, which in turn dissolves the refractory metalconstituents, the molten mass being stirred with a suitable rod oftungsten, molybdenum or silicon.

After the mass has reached the molten condition and the molybdenum,tungsten and manganese are uniformly dissolved and stirred into themolten metal, the resultant alloy may then be poured into asuitablemold, depending upon the shape of bar that is to-be formed.

Our-alloy-compositlon may also be produced by mixing the powders of thevarious constituents of our alloy in the proper proportion and thenball-milling and pressing the same and sintering at a tempertureslightly below the melting point of the bar until a uniform homogeneoussintered alloyed bar is produced.

The resultant composition is a silvery looking, non-magnetic,non-corrosive metal which may then be mechanically worked into anysuitable shape. It is usually annealed and may also be drawn down intovery fine wire with intermediate annealing. If the wire is to be usedfor radio tube purposes, it is degasified by heating the same at ayellow heat in an atmosphere of hydrogen, thereby dispelling allobjectionable occluded gases and saturating the wire with The alloy mayalso be rolled down into very thin sheet metal with intermediateannealing, which sheet maybe punched out into various forms and may beused for'contact surfaces in electrical circuits and even for thepurpose of brazing refractory metals together, or brazing together hightemperature thermostatic metals.

It gives excellent results especially for the welding together of nickelchrome compositions. The addition of the refractory metals, such asmolybdenum and tungsten, uranium, etc., tends to increase the hardnessof the Monel metal and also tends .to degasify the alloy. Our resultantalloy in its final state is usually composed of the standard Monel metal(28% copper and 72% nickel), having added thereto to 3% manganese, 4% tomolybdenum and 1% to 5% tungsten.

Our new alloy, when worked into fine wire to be used as grid wires inradio tubes, will result in grids that will give lower grid emissionthan the grid wires at present known in the art, thereby giving improvedradio tube performance.

This wire is particularly well suited to function as improved grid wirewhen its surface is etched chemically or electrolytically or coated witha thin film of carbonaceous coating. By etching or coating the surface,or by a combination of both etching and coating with carbon, the

surface of the wire radiates heat at an increased rate more than itwould if it were a bright wire,

thereby reducing the operating temperature of the grid. This is-highlydesirable in the multi-grid type of tube, where excessive localizedheating impairs the proper functioning of the tube.

This etching may be done by drawing the wire through an electrolyticbath' composed of an alkaline ferro-cyanide or other suitableelectrolyte, the wire constituting one side of the circuit. Afteretching and washing, the wire may be drawn through a colloidalsuspension of graphite or carbon or a deflocculated graphite paste,thereby coating the wire with a thin film of this carbon paste, thendrawing the same over a flame and baking it intimately onto the wire.

As an alternative method of coating the wire, we may heat the wire in acarbonaceous atmosphere, thereby depositing a thin film of carbon on thesurface of either the'clean or the etched wire.

What we claim as new is:-

l. A non-corrosive alloy comprising 62% nickel, copper, 2% manganese,10% molybdenum and 1% tungsten.

2. An alloy comprising to 5% manganese, 4% to 20% molybdenum and 1% to5% tungsten, the balance of the alloy comprising Monel metal composed ofsubstantially 28% copper and substantially 72% nickel.

JACOB KURTZ. CLEMENS A. LAISE.

